Noise optimisation. Fix code style issues. Add info to readme

README.txt

@@ -1,4 +1,10 @@
-meru 0.3.0 by paramat
-For latest stable Minetest and compatible back to 0.4.8
+meru 0.3.1 by paramat
+For Minetest 0.4.12 and later
 Depends default
 License WTFPL
+
+Meru mod is a vertical 1 dimensional realm, 1D referring to large scale structure, and can act as a vertical connector between horizontal realms, such as the ground and the floatlands.
+A single spike shaped mountain is created in newly generated chunks, at a random location within a chosen area, by default this area is +/-1024 for use in a new world, to add a mountain to an existing world you need to edit these area parameters to a completely ungenerated part of your world.
+For testing this mod or for cheating edit parameter COORD = true, the co-ordinates of the mountain will be printed to terminal while within the generation area.
+The mountain is a hollow cone made of stone and desert stone, with a smooth transition across biome boundaries. By default the height is 2km. There are a few cave entrances on the surface, these 'fissure system' caves expand under the surface helping the creation of a path upwards. If the mountain generates over water you can use the central conical void to jump down the last few hundred metres.
+There are many parameters for fine tuning the structure, some parameters change smoothly with height or distance from the center. Reducing noise to zero at the center creates a perfect spike as a summit. Constant noise throughout often creates floating islands at the summit. Choosing zero noise throughout creates a smooth geometric conical shape. There is a parameter CONVEX to control whether the basic conical structure bulges outwards or is pinched inwards in the middle.

init.lua

@@ -1,10 +1,3 @@
--- meru 0.3.0 by paramat
--- For latest stable Minetest and compatible back to 0.4.8
--- Depends default
--- License WTFPL
-
--- Voxelmanip version
-
 -- Parameters
 
 local COORD = false -- Print tower co-ordinates to terminal (cheat)
@@ -18,9 +11,11 @@ local BASRAD = 64 -- Average radius at y = -32
 local HEIGHT = 2048 -- Approximate height measured from y = -32
 local CONVEX = 0.6 -- Convexity. <1 = concave, 1 = conical, >1 = convex
 local VOID = 0.4 -- Void threshold. Controls size of central void
-local NOISYRAD = 0.2 -- Noisyness of structure at base radius. 0 = smooth geometric form, 0.3 = noisy
+local NOISYRAD = 0.2 -- Noisyness of structure at base radius.
+						-- 0 = smooth geometric form, 0.3 = noisy.
 local NOISYCEN = 0 -- Noisyness of structure at centre
-local FISOFFBAS = 0.02 -- Fissure noise offset at base. controls size of fissure entrances on outer surface
+local FISOFFBAS = 0.02 -- Fissure noise offset at base,
+						-- controls size of fissure entrances on outer surface.
 local FISOFFTOP = 0.04 -- Fissure noise offset at top
 local FISEXPBAS = 0.6 -- Fissure expansion rate under surface at base
 local FISEXPTOP = 1.2 -- Fissure expansion rate under surface at top
@@ -47,8 +42,6 @@ local np_fissure = {
 	persist = 0.5
 }
 
--- End of parameters
-
 -- 2D noise for biome. Parameters must match mgv6 biome noise
 
 local np_biome = {
@@ -60,6 +53,8 @@ local np_biome = {
 	persist = 0.5
 }
 
+-- Stuff
+
 local cxmin = math.floor((XMIN + 32) / 80) -- limits in chunk co-ordinates
 local czmin = math.floor((ZMIN + 32) / 80)
 local cxmax = math.floor((XMAX + 32) / 80)
@@ -89,6 +84,12 @@ minetest.register_node("meru:destone", {
 	sounds = default.node_sound_stone_defaults(),
 })
 
+-- Initialize noise objects to nil
+
+local nobj_structure = nil
+local nobj_fissure = nil
+local nobj_biome = nil
+
 -- On generated function
 
 minetest.register_on_generated(function(minp, maxp, seed)
@@ -120,7 +121,6 @@ minetest.register_on_generated(function(minp, maxp, seed)
 	local x1 = maxp.x
 	local y1 = maxp.y
 	local z1 = maxp.z
-	print ("[meru] chunk minp ("..x0.." "..y0.." "..z0..")")
 	
 	local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
 	local area = VoxelArea:new{MinEdge = emin, MaxEdge = emax}
@@ -130,12 +130,17 @@ minetest.register_on_generated(function(minp, maxp, seed)
 	local c_destone = minetest.get_content_id("meru:destone")
 
 	local sidelen = x1 - x0 + 1
-	local chulens = {x=sidelen, y=sidelen, z=sidelen}
-	local minposxyz = {x=x0, y=y0, z=z0}
+	local chulens3d = {x = sidelen, y = sidelen, z = sidelen}
+	local chulens2d = {x = sidelen, y = sidelen, z = 1}
+	local minpos3d = {x = x0, y = y0, z = z0}
 
-	local nvals_structure = minetest.get_perlin_map(np_structure, chulens):get3dMap_flat(minposxyz)
-	local nvals_fissure = minetest.get_perlin_map(np_fissure, chulens):get3dMap_flat(minposxyz)
-	local nvals_biome = minetest.get_perlin_map(np_biome, chulens):get2dMap_flat({x=x0+150, y=z0+50})
+	nobj_structure = nobj_structure or minetest.get_perlin_map(np_structure, chulens3d)
+	nobj_fissure = nobj_fissure or minetest.get_perlin_map(np_fissure, chulens3d)
+	nobj_biome = nobj_biome or minetest.get_perlin_map(np_biome, chulens2d)
+
+	local nvals_structure = nobj_structure:get3dMap_flat(minpos3d)
+	local nvals_fissure = nobj_fissure:get3dMap_flat(minpos3d)
+	local nvals_biome = nobj_biome:get2dMap_flat({x = x0 + 150, y = z0 + 50})
 
 	local nixyz = 1 -- 3D noise index
 	local nixz = 1 -- 2D noise index
@@ -183,4 +188,3 @@ minetest.register_on_generated(function(minp, maxp, seed)
 	local chugent = math.ceil((os.clock() - t0) * 1000)
 	print ("[meru] " .. chugent .. " ms")
 end)
-